Watson and Crick A Using information from many

Watson and Crick A. Using information from many researchers of their time, they assembled the first complete model of DNA as a double helix in 1953 B. Double helix = two strands of DNA twisted into a spiral staircase C. Their model explained 2 things: 1. How information is stored in DNA 2. How DNA could be copied

Notes – Structure of DNA

DNA is a polymer

DNA is a polymer • Nucleotide monomers have 3 parts: 1. Phosphate group 2. Sugar (deoxyribose) 3. Nitrogenous Base:

DNA is a polymer • Nucleotide monomers have 3 parts: 1. Phosphate group 2. Sugar (deoxyribose) 3. Nitrogenous Base: • • Guanine (G) Thymine (T) Adenine (A) Cytosine (C)

DNA is double-stranded

DNA is double-stranded 1. Two strands of nucleotides are held together by hydrogen bonds

DNA is double-stranded 1. Two strands of nucleotides are held together by hydrogen bonds 2. Base-pairs: The two strands have A bonded to T and G bonded to C

DNA is double-stranded 1. Two strands of nucleotides are held together by hydrogen bonds 2. Base-pairs: The two strands have A bonded to T and G bonded to C 3. The two strands are complementary and are arranged in opposite directions

Eukaryotic DNA forms chromatin • Chromatin = DNA wrapped around proteins • During cell division, chromatin condenses into chromosomes

Eukaryotic DNA forms chromatin • Chromatin = DNA wrapped around proteins • During cell division, chromatin condenses into chromosomes